1. Field of the Invention
The embodiments herein generally relate to atomic force microscopy (AFM), and, more particularly, to methods of forming AFM probes for analyzing substrates.
2. Description of the Related Art
Atomic Force Microscopy (AFM) is often used as a method of characterizing critical dimensions of width, height, profile, and surface chemistry for structures on a semiconductor substrate. In order to characterize the topography of trench features of silicon devices, it is desirable to fabricate AFM probe tips that have an angled feature near the active end of the probe tip. Conventionally, these probe tips are fabricated by etching silicon features with an angled structure or foot at one end of the silicon feature.
FIG. 1 illustrates a conventional AFM probe apparatus. Generally, the AFM probe 1 comprises a probe arm 2 terminating with a tip 3. The probe tip 3 is then used to analyze the profile of the surface 5 of a substrate 4. A particular feature 6 on the surface 5 of the substrate 4 may have an undercut feature defined by inwardly sloping sidewalls 7. The topography of this feature 6 generally makes it difficult for the probe tip 3 to fully analyze all of the surface features of the substrate 4.
Therefore, it remains desirable to develop additional methods of manufacturing AFM probe tips more reproducibly, and from other materials than silicon, which can be more durable and have a smaller dimension than conventional AFM probe tips, which can be used to analyze substrates with an angled topography, and which can be used for exploring the chemistry of the surfaces of substrate topography.